/* 导航栏模块的样式 */
nav, article, footer {
  display: block;
}
a {
  text-decoration: none;
  color: #333;
}
body {
  background-color: #f3f5f7;
}
nav {
  box-shadow: 0px 0px 10px rgba(0, 0, 0, 0.5);
 }
.nav-container {
  min-height: 100px;
}
.nav-link {
  font-size: 20px;
}
.nav-link.active {
  border-bottom: 2px solid #00a4ff;
}
/* 轮播图模块 */
.course-banner {
  margin-top: 116px;
}
.course-banner .recommend {
  background-color: #fff;
  box-shadow: 1px 1px 2px 0px rgba(211, 211, 211, 0.5);
}
.course-banner .recommend a {
  padding: 20px;
  font-size: 16px;
  color: #333;
  border-radius: 5px;
}
.course-banner .recommend a i {
  float: left;
  width: 38px;
  height: 33px;
  margin: -5px 8px;
  background: url("../images/pic.png") no-repeat 0 0;
}
.course-banner .recommend ul li.fathli2 i {
  background-position: -38px 0;
}
.course-banner .recommend ul li.fathli3 i {
  background-position: -80px 0;
}
.course-banner .recommend ul li.fathli4 i {
  background-position: -120px 0;
}
.course-banner .recommend ul li.fathli5 i {
  background-position: -160px 0;
}
.course-banner .recommend ul li:hover {
  background-color: #f3f5f7;
}
/* 视频教程模块 */
.course-free .col p {
  font-size: 14px;
  line-height: 20px;
  color: #999;
}
.course-free .col p span {
  color: #fa6400;
}
.course-free .col p i {
  font-style: normal;
}
.title {
  font-size: calc(0.8rem + 1vw);
  text-align: center;
  letter-spacing: 1px;
}
.title-text {
  font-size: calc(0.5rem + 0.7vw);
  text-align: center;
  letter-spacing: 1px;
  color: #333;
}
.title-text .startLearning {
  color: red;
}
/* 视频教程模块——导航区域 */
.course-line {
  padding: 30px 0;
}
.course-line .course-tabs {
  border-bottom: 1px solid #ccc;
  flex-wrap: nowrap;
  overflow-x: auto;
}
.course-tabs li {
  padding-left: 20px;
  flex: 0 0 108px;
}
.course-tabs li a {
  color: #333;
  padding-bottom: 25px;
  font-size: 14px;
}
.course-tabs li a:hover,
.course-tabs li a.active {
  color: red;
  border-bottom: 3px solid #E92322;
}
.icon-container {
  align-items: center;
  justify-content: center;
}
.course-tabs li a i {
  float: left;
  width: 60px;
  height: 60px;
  margin: -5px 8px;
  background: url("../images/anijavaee.png") no-repeat 0 0;
  background-size: 60px;
  margin: 0 auto 8px;
}
.course-tabs li.icon-web i {
  background-image: url("../images/aniweb.png");
}
.course-tabs li.icon-python i {
  background-image: url("../images/anipython.png");
}
.course-tabs li.icon-ai i {
  background-image: url("../images/aniai.png");
}
.course-tabs li.icon-ui i {
  background-image: url("../images/aniui.png");
}
.course-tabs li.icon-test i {
  background-image: url("../images/anitest.png");
}
.course-tabs li.icon-xmt i {
  background-image: url("../images/anixmt.png");
}
.course-tabs li.icon-pm i {
  background-image: url("../images/anipm.png");
}
/* 视频教程模块——标签页内容区域 */
.course-box {
  height: 150px;
  background: #fff;
  box-shadow: 1px 2px 3px 1px #d8d8d8;
  margin-top: 20px;
  font-size: 12px;
  color: #666;
}
.course-box p {
  margin-bottom: 2px;
}
.course-box .course-box-left h3 {
  font-size: 16px;
  padding: 20px 0 5px;
  margin: 0;
  color: red;
}
.course-box .course-box-right {
  float: right;
  width: 108px;
  height: 100%;
  text-align: center;
  position: relative;
  border-left: 1px dashed #ccc;
}
.course-box .course-box-right::before,
.course-box .course-box-right::after {
  content: "";
  position: absolute;
  left: -6px;
  width: 12px;
  height: 12px;
  border-radius: 6px;
  background: #f5f5f5;
}
.course-box .course-box-right::before {
  top: -6px;
  box-shadow: 0 -2px 2px #d8d8d8 inset;
}
.course-box .course-box-right::after {
  bottom: -6px;
  box-shadow: 0 2px 2px #d8d8d8 inset;
}
.course-box.active .course-box-right p {
  color: #fff;
}
.course-box-right p:first-of-type {
  margin-bottom: 0;
  margin-top: 40px;
  color: #E92322;
}
.course-box-right p:first-of-type b {
  font-size: 40px;
}
footer {
  background-color: #f8f9fa;
  color: #f4f4f4;
  padding: 10px;
}
.container h2{
  text-align: center;
}
.video-container {
  position: relative;
  overflow: hidden;
  padding-top: 56.25%; 
}
.video-container iframe {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}

